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Mobile Acetylene Cylinders : Hazard Potential Not To Be Underestimated!

Mobile acetylene cylinders : Hazard potential not to be underestimated!

  • Flash
Mobile acetylene cylinders are present in all sectors of activity owing to their common use on welding machines. Even if they look like risk free, these cylinders are real hazard potential ! Five major accidents in France since the beginning of 2018 drive us to remind to users and owners the risks associated to these cylinders.
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Hydrofluoric Acid : The Worst Of All Acids?

Hydrofluoric acid : the worst of all acids?

  • Flash
Despite being produced 200 times less than sulphuric acid (1 M vs. 200 M tonnes/year), the ARIA database has recorded nearly 80 accidents involving hydrofluoric acid (HF) (vs. 220 for H2SO4). A series of recent accidents serves to recall its hazards, especially the serious consequences in the event of its release...
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Mixing of incompatible products

  • Fact sheet
Transfer of chemicals between fixed and mobile tanks may cause mixtures of incompatible products. This risk is all the more pernicious as the mixture usually involves "classic" substances and widely used: bleach, acid ... This fact sheet presents some lessons learnt from the accidentology.
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Accidents Associated With Chlorine

Accidents associated with chlorine

  • Study
This summary report was established based on information collected from 557 French accidents (251 cases) or foreign accidents (306 cases) which took place between January 1917 and May 2003 and which are recorded in the ARIA database. This document should be of specific interest to installations implementing large quantities of chlorine (chemical plants, paper mills, metallurgy…), as well as companies involved in its transport.
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Mix Of Incompatible Products

Mix of incompatible products

  • Flash
The accidents presented in this flash involve chemical reactions between incompatible products inadvertently placed into contact with one another. Encountered in all types of activities, such accidents are frequent and occur not only during the delivery of chemical products (wrong destination reservoir, etc.), during handling or cleaning operations (mistaken chemical substance, simultaneous use of 2 incompatible products), but also when emergency interventions deploy inappropriate resources for the type of accident at hand (use of water on a fi [...]
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Extended release of mercaptans from a chemical plant

  • Accident report
  • FRANCE

Around 8:00 a.m., an operator smelled mercaptans (strong-smelling gas < 1 ppb, toxic in high concentrations) in the zinc dialkyldithiophosphate (ZDDP) unit of a site that manufactures lubricant additives. He collected a sample of mercaptan that had been sitting in the adjustment tank for two days awaiting transfer when the high-temperature alarm went off in the control room. Around 9:00 a.m., analyses confirmed that the mercaptan had thermally decomposed. An inerting test involving the addition of a mixture of zinc oxide and water failed at around 11:00 a.m. because of technical difficulties that delayed preparation of the neutralisation mixture in a mobile mixer (plug/socket connection issues, mixture prepared too quickly). The gas treatment system at the unit overloaded, allowing a strong-smelling cloud of gas to drift off site. At 10:00 a.m., the plant operator implemented the internal emergency plan and informed the regional prefecture at around 11:30 a.m. Thirty-three communities were alerted via various emergency alerts. Neutralization tests conducted in the late evening failed. The wind then shifted, blowing the smell south-east to the Paris area and north-west over the Channel and towards the south of England during the night. Tens of thousands of people were bothered by the unpleasant aroma, with some complaining of nausea, headache and vomiting. Emergency services responded to over 20 calls in the Rouen area. The prefect put together an information team on Tuesday morning and implemented an external emergency plan at 10:35 a.m. From Wednesday morning to Friday evening, a new method made it possible to 'safely' neutralise the 36 tonnes of decomposing mercaptan in batches of 12 tonnes and haul it by lorry to an incineration plant. According to upper bound calculations, the decomposition released 95 kg of hydrogen sulphide, which was eliminated by the treatment system, and 545 kg of mercaptans that were not totally treated (272 kg released into the air). The accident received extensive media attention in France and abroad due to the area covered by the gas cloud. The tank was rinsed and the external emergency plan was ended on 6 February. The operating losses are temporarily estimated at several hundred thousand euros (plant shut down for the duration of the accident, ZDDP shop shut down for three months afterwards).

Multiple causes were identified:

  • On Friday 18 January, an operator mistakenly turned on the adjustment tank's mixer instead of the recirculation pump via the unit's control panel. A batch of mercaptan at 94 °C, transferr [...]
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Explosion And Fire On An Acrylic Acid Tank At A Chemical Plant

Explosion and fire on an acrylic acid tank at a chemical plant

  • Accident report
  • JAPON

During his shift, an employee of a special chemical products plant noticed at 1:20 pm a release of white smoke through the vents on an intermediate storage tank containing acrylic acid (AA, C3H4O2, flammable and corrosive substance, boiling point: 141°C). The tank (70 m³, 75 mm stainless steel shell) had been filled in preparation for a distillation column filling test; moreover, it was heat insulated and inerted with nitrogen. The employee sounded the alarm; a crew of internal fire-fighters attempted to stop the exothermic polymerisation rea [...]

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Uncontrolled Emissions Subsequent To A Decomposition Reaction Inside A Dryer

Uncontrolled emissions subsequent to a decomposition reaction inside a dryer

  • Accident report
  • FRANCE

At a Seveso-classified plant producing substances used in medical imaging, a temperature control defect on a biconical dryer caused product decomposition during the drying cycle. The subsequent pressure surge led, around 10 pm, to the explosion of part of the glass piping (a pipe elbow connecting the dryer to its vacuum pump). At the time, the dryer was holding 1,800 kg of a mix containing ethanol and an product releasing iodine (I2), hydrochloric acid (HCl) and nitrogen oxides (NOx) when decomposing. I2 was discharged into the atmosphere via b [...]

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VCE In A Waste Treatment Tank Of A Pharmaceutical Plant

VCE in a waste treatment tank of a pharmaceutical plant

  • Accident report
  • ITALIE

An explosion occurred around noon while conducting hot work (with a disc saw) on a 320-m³ fixed-roof tank at a pharmaceutical plant employing 240 personnel. The tank cover was blasted 20 m away and the subcontractor performing cutting works was killed. Three other subcontractors and a plant employee were severely burnt and injured by the shock wave. Notified by neighbours and not by the operator, fire-fighters arrived on the scene 15 min after the explosion and promptly extinguished the fire. Municipal and provincial authorities as well as Reg [...]

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